$ERF is one of biggest losers #stocks today. read more:

Enerplus Corporation Common Sto (symbol: ERF) was one of the worst losers
of the trading day today (2016-01-11), losing -11.87%. The number of shares
that changed hands was 1,485,290, or about 1 times the average daily volume
in the stock.
The closing price was $2.45, amounting to a market cap of $505,920,000,
about -81.38% off the highest price in the last 12 months. The stock has
been trading at a range between $2.44 and $13.16.
ERF is in the Oil & Gas Production industry, part of the Energy sector.